Heartburn

Smoking a cigarette helps relieve heartburn.

False.

Actually, cigarette smoking contributes to heartburn. Heartburn occurs when the lower esophageal sphincter (LES)--a muscle between the esophagus and stomach--relaxes, allowing the acidic contents of the stomach to splash back into the esophagus. Cigarette smoking causes the LES to relax.

source: http://digestive.niddk.nih.gov/ddiseases/pubs//facts/index.htm